Ok I have a 93 3.9l and lately its been acting funny when I start it it idles at 1k then it works it way to about 500 well I figured that was normal but when I'm driving and change gears the rpms don't drop until I'm in the next gear and also if I just barely touch the gas then it will go from 500 to 1500 for a few seconds before returning to 500.

but that's not all today I had to leave in a rush and I didn't have a chance to warm it up and it really acted up every time I hit the gas it would almost die and then it goes up to 2k rpms idk what in the world is going on

 

The idle problem most likely is a bad IAC Idle Air Control valve.

 

Could it be from running too rich?

 

Clean the iac valve with carb cleaner or something. This should help. If It's dirty it cannot do its job which is to adjust the amount of air coming into the tb at an idle